(a) Field of the Invention
This invention relates to an apparatus for testing the contamination of industrial liquids and more particularly for testing the density of mixed or unmixed organisms in such liquids.
(b) Description of the Prior Art
The presence of organisms in an industrial liquid, for example in a metal working fluid, causes rapid deterioration of the fluid and, in the field of cutting oils or lubricants, can cause machine failure. Also, pathogens harmful to man can grow readily in metal working liquids, even when numerous chemical agents are added to kill such organisms. Many of the chemical products used to control such organisms represent serious toxicity hazards and can affect the usefulness of the metal working liquids. To achieve a balanced chemical control requires a very rapid and quantitative testing of the organism density in the liquid.
An important object of this invention is to provide an apparatus for quantitatively assaying organism density in a liquid over a relatively short and known time interval, say in two to twelve minutes, in a liquid sample with no pretreatment of the sample.
In one embodiment the vessel is closed with a stopper. It is desired to measure pressure increases in the vessel's headspace contained above the surface of the liquid. With the apparatus of this invention, the pressure measurements can be made continuously or at different times without loosing the sealing effectiveness of the stopper and, hence, the required measurement accuracy. In another embodiment, it is desired to detect a fixed pressure rise in the gas contained in the vessel.